Over a long period of time, glass forming machines, e.g., of the IS type, have been used to produce suitable types of glass articles. Generally, control systems for such glass forming machines have a centralized architecture, where peripheral units are connected to a single centralized control system.
One such type of control systems is shown in FIG. 1.
As shown in FIG. 1, a glass forming machine 100 divides into a plurality of sections 102, 104, 106, 108. The peripheral control unit of each such section is connected via dedicated cables 110, 112, 114, 116 to a central control unit 118.
The control system architecture shown in FIG. 1 is disadvantageous in that this centralized solution requires for each functionality—e.g., solenoid valve—a lead of a cable and further a commonly used return cable. Further, the lead is also used to supply energy necessary for operation of the solenoid valve. For usual applications, the distance of cable is 50 m or even more. As currents of approximately 350 mA flow per solenoid valve, it is necessary to have an increased lead cross-section to reduce voltage drop, e.g., with a cable distance exceeding 50 m, a lead cross-section of 1 mm2. A typical number of lead per valve block cable amounts to 50, and therefore the cable will have a diameter of approximately 30 mm. At the IS machine side, the cable will in addition be protected with a flexible steel armoured conduit, which increases the diameter even more.
To overcome these deficiencies in EP 1 184 754 A2, there is proposed a control system for a glass forming machine comprising a central control unit, a plurality of intelligent peripheral units, and a serial bus interposed between the central control unit and the different intelligent peripheral units. While such an approach improves flexibility at least to some extent, nevertheless, serious drawbacks remain. A first such drawback is that the provision of a serial bus imposes critical time restrictions for the transfer of data between the central control unit and the peripheral units. Yet another restriction is that the division of functionality between a peripheral unit being provided in relation to sections of the glass forming machine and a central control unit is maintained as shown in FIG. 1, which severely restricts control system architecture flexibility.